The first is the imaging of the lungs, which is the X-ray chest radiograph; the second is the sputum examination, including sputum smear and sputum culture; the third is the pharyngeal swab; and the fourth is the alveolar lavage fluid examination. X-ray and chest CT are the easiest tests for pneumonia in the lungs, which can be used to understand the severity of the disease through its imaging changes, whether the infected lesions in the lungs are complicated by emphysema, Pulmonary atelectasis, pleural effusion, etc. can be used to assess the efficacy of the entire pneumonia treatment process. Complete sputum smear and sputum culture of pneumonia can be used to clarify the etiologic basis of the patient’s inflammatory lung infection, and alveolar lavage fluid examination can be performed for deep tissue infections to further clarify the pathogenic status of the patient’s lung infection.